The Mouse Biology Shared Resource will dictate resources and expertise to provide Mouse Model Creation Services (generation of knockout and transgenic mouse strains, genes targeting by homologous recombination in ES cells, procurement, importation and rederivation to generate pathogen-free mice, cryopreservation and resuscitation of embryos and germplasm, assisted reproduction procedures), Mouse Husbandry and Maintenance Services (colony management, health surveillance and disease prevention, sharing and distribution of strains), and Mouse Phenotyping Services (gross and microscopic pathology, small animal imaging procedures) to support researchers participating in the UC Davis Cancer Center. Mouse Biology Shared Resource services are available to UC Davis Cancer Center researchers. All services are offered routinely and have been tested and proven effective. CORE Services are divided into three categories: 1) Mouse Model Creation Services; 2) Mouse Husbandry and Maintenance Services; and 3) Mouse Phenotyping Services. The Mouse Biology Shared Resource is available to members of the UC Davis Center, and many have made use of the aforementioned services to conduct cancer-related research.